Ignition system for a smoking machine

ABSTRACT

The present invention provides an ignition system for a smoking machine, comprising a heat source ( 2 ) that is adapted for emitting heat for igniting one end of a smoking article which is held by a smoking machine; an automatic sensor ( 3, 4 ) which is adapted for detecting the position of said end of the smoking article; and control means in communication with said sensor ( 3, 4 ), which are adapted for automatically adjusting the operation of said heat source ( 2 ) and/or for automatically adjusting relative movement of said heat source and/or of said article, depending on the position of said end as detected by said sensor ( 3, 4 ), such as to enable successful ignition of said end by said heat source. The invention further provides a kit of components for forming an ignition system in accordance with the invention, and a smoking machine comprising an ignition system in accordance with the invention.

The present invention relates in general to improvements in and relatingto smoking machines for smoking articles such as cigarettes, cigars andcigarillos. More particularly, the invention relates to an improvedignition system for igniting smoking articles for smoking by a smokingmachine.

Regular testing of cigarettes on a smoking machine is an important partof any cigarette manufacturing process. A smoking machine serves tocreate a repeatable standardised environment for the analytical smokingof cigarettes. International and national standards, including ISOstandard 3308 (2000), have been put in place for standardising theoperation of smoking machines.

A smoking machine typically comprises at least one holder for acigarette, and a puffing means for drawing air in controlled fashionthrough the cigarette in regular short puffs in order to smoke thecigarette. The smoking machine typically comprises or is adapted toengage with at least one lighter tool which comprises a heat source suchas a resistive coil for lighting the cigarette. The machine usually alsocomprises or is adapted to engage with a variety of other tools,including tools for measuring or observing particular smokingcharacteristics, such as puff profile and leak check tools and/or airvelocity tools.

It is desirable that the lighter tool should be capable of lighting thecigarette at the first attempt. Multiple attempts at lighting thecigarette may result in pre-charring, which may alter the smokingcharacteristics of the cigarette or otherwise disrupt any measurementswhich are to be taken. ISO standard 3308 (2000) indeed requires that asmoking machine should be capable of lighting cigarettes at the firstattempt and without pre-charring. Furthermore, the need for multipleattempts at lighting is clearly inefficient.

Evidently, the distance separating the heat source of the lighter toolfrom the cigarette end will have a profound effect on the success ofignition. If the heat source is too remote from the cigarette end, thenthe chances of successful lighting at first attempt will be diminished.On the other hand, if the heat source is too close to the cigarette,then the ignition process may result in heat damage to the cigarettewhich may alter its smoking characteristics. Actual contact between theheat source and the cigarette during ignition is particularlyundesirable and is not permitted under ISO standard 3308 (2000).Typically, a separation of 0.5-1.0 mm between the heat source and thecigarette end at the point of ignition is viewed as desirable.

Some difficulty has however been encountered in achieving precisionpositioning (to within about 1.0 mm) of the cigarette and lighter tool.Once a cigarette has been loaded into a smoking machine, the position ofthe unlit tip with respect to the smoking machine depends primarily uponthe length of the cigarette and the depth of insertion of the cigaretteinto the smoking machine. Owing to the tolerances of manufacturingprocesses, the lengths of individual cigarettes from a batch typicallyvary within a range of 1-2 mm, giving rise to a correspondinguncertainty in the predicted length of a cigarette from the batch.Meanwhile, the depth of insertion of a given cigarette into a givensmoking machine may also vary by around 1-2 mm, depending primarily onthe force with which the cigarette is inserted into the machine. Thecombined effect of these uncertainties is an overall uncertainty of upto 4 mm in the predicted location of any single cigarette tip withrespect to the smoking machine. Precision positioning of the lightertool with respect to each cigarette tip, based on the predicted locationof the cigarette tip, is therefore impossible.

Various attempts have been made to address this problem. According toone method, individual cigarettes are adjusted by hand followinginsertion into the smoking machine, such that each cigarette protrudesby a predetermined distance from the machine. This method successfullyachieves uniform positioning of cigarettes within the smoking machinefor the purposes of ignition, but is time-consuming and inefficient.Attempts have also been made to design lighter tools which are capableof reliably lighting cigarettes over a range of distances varying byseveral millimetres. Although the benefits of automation are preserved,such tools however have costly power requirements in operation, and maycause heat damage to cigarettes.

There remains therefore a need for an improved apparatus forautomatically and reliably lighting cigarettes for smoking by a smokingmachine.

According to one aspect of the present invention therefore, there isprovided an ignition system for a smoking machine, comprising a heatsource that is adapted for emitting heat for igniting one end of asmoking article which is held by a smoking machine; an automatic sensorwhich is adapted for detecting the position of said end of the smokingarticle; and control means in communication with said sensor, which areadapted for automatically adjusting the operation of said heat sourceand/or for automatically adjusting relative movement of said heat sourceand/or of said article, depending on the position of said end asdetected by said sensor, such as to enable successful ignition of saidend by said heat source.

According to another aspect of the present invention, there is provideda smoking machine comprising holding means for holding a smoking articlesuch as to expose one end thereof, puffing means positioned adjacent theother end of the smoking article for drawing air through the smokingarticle, and an ignition system in accordance with the invention forigniting said one end of the smoking article such that the article canbe smoked by the smoking machine.

In use of the present invention, the sensor acts to detect the positionof the end of the smoking article, and communicates information in thisregard to the control means. Based on this information, the controlmeans makes automatic adjustments as necessary to the operation of theheat source, and/or to relative movement of the heat source and/or saidsmoking article, such as to enable successful ignition of the smokingarticle by the heat source. Successful ignition may denote ignition atthe first or the second, preferably the first, attempt. Furthermore,successful ignition may denote ignition of the smoking article withoutany undesired heat damage to the article and/or without contact betweenthe smoking article and the heat source during emission of heat by theheat source.

Said ignition system may be adapted for igniting a plurality of smokingarticles. Thus, said ignition system may comprise a plurality of heatsources, each of which is associated with a respective automatic sensorin the manner hereinbefore described.

It will be understood that the heat source may emit heat for ignitingthe end of said smoking article by conduction, by convection or byradiation, or by any combination of conduction, convection andradiation. More typically, said heat source may emit heat by radiationor convection or by a combination of radiation and convection. Said heatsource may, for example, comprise a heatable coil, plate, element orother surface, such as a resistive coil, resistive plate, or otherresistive heating element or surface heated thereby. Such a heat sourcewill emit heat for igniting the end of said smoking article by acombination of electromagnetic radiation and convection of heated air.The power of said heat source may be in the region of 30-100 W, such asbetween 40-60 W, such as about 50 W. Alternatively, said heat source maycomprise a laser, or an incandescent bulb such as a halogen bulb, forexample a halogen bulb of about 120-200 W, which will emit heat forigniting the end of said smoking article primarily by electromagneticradiation. Heat sources of all of these types are known in the art. Saidheat source may conveniently be powered by electricity.

As will be appreciated by the skilled man, once the location of the endof the smoking article has been accurately determined, a variety ofadjustments may be made to the components of the ignition system and/orthe smoking machine so as to ensure successful ignition of the smokingarticle by the ignition system.

The distance separating said heat source from said end of the articleduring emission of heat from the heat source is typically a keyparameter affecting the reliability and success of ignition, regardlessof the manner in which heat is emitted by the heat source. Thus, saidcontrol means may be adapted to automatically adjust relative movementof said heat source and/or said smoking article, such that apredetermined distance separates said heat source from said end of thesmoking article, whereby said end of the smoking article can besuccessfully ignited by the heat source.

Suitably, therefore, said heat source may be capable of movement withrespect to said smoking article, and said control means may be adaptedfor controlling movement of said heat source, whereby the heat sourceunder the control of said control means can be moved into or halted at aselected position. Alternatively, or in addition, said control means maybe adapted for controlling movement of a smoking article held by asmoking machine, whereby said smoking article under the control of saidcontrol means can be moved into or halted at a selected position. Bythus controlling relative movement of said heat source and/or saidsmoking article in view of the known position of said end of the smokingarticle, a predetermined distance separating said heat source from saidend of the smoking article may readily be achieved.

Said sensor may be arranged such as to detect the end of a smokingarticle when said end is disposed at said predetermined distance fromthe heat source, or when said end is positioned such that aftersubsequent movement of said smoking article and/or said heat sourcealong a pre-set locus, said end will be disposed at said predetermineddistance from the heat source. Alternatively, said ignition system maybe arranged such that following detection of said end of the smokingarticle by said sensor, said heat source and/or said smoking article aremoved under the control of the control means such as to achieve saidpredetermined distance between said heat source and said end of thesmoking article.

Suitably, said control means may be adapted to ensure that said heatsource and said smoking article remain out of contact with one anotherduring emission of heat by the heat source.

Additionally or alternatively, said control means may be adapted toautomatically adjust the operation of said heat source followingdetection of the end of a smoking article by the sensor, such as toenable successful ignition of said end of the smoking article by theheat source. Parameters of the operation of the heat source which mayaffect the reliability and success of ignition include the temperatureof the heat source; the channelling of heat from the heat source to theend of the smoking article; the level and wavelength range ofelectromagnetic radiation that is applied by the heat source to the endof the smoking article; the length of time for which heat is applied tothe end of the smoking article for igniting the article; and the timingof the application of heat to the end of the smoking article forigniting the article with respect to the “puff cycle” of a smokingmachine. By adjusting any or all of these parameters, the control meansmay serve to enable successful ignition of a smoking article by the heatsource without any or any further adjustments in relative movement ofthe heat source and/or said smoking article. Said control means maytherefore be adapted for calculating the type and extent of anyadjustments to any of these parameters which may be required forenabling successful ignition, in view of the known position of the endof the smoking article (as detected by said sensor), and for securingthe performance of such adjustments. It will be appreciated however thatsaid control means may be adapted for adjusting any or all of theaforementioned parameters of the operation of the heat source inaddition to adjusting relative movement of said heat source and/or saidsmoking article.

Where said heat source is adapted for emitting heat by air convectionfor igniting said end of the smoking article, said control means may beadapted to automatically adjust the temperature of the heat source, theadjustment depending upon the location of said end, as detected by thesensor. Clearly, where said end is located at a greater distance fromsaid heat source, successful ignition can nonetheless be achievedthrough increasing the temperature of the heat source. Conversely, wheresaid end is located at a smaller distance from said heat source,successful ignition without undue heat damage to the smoking article cannonetheless be attained through decreasing the temperature of the heatsource.

Variation in the temperature of the heat source may for example beachieved by adjusting the power input which energises the heat source.Thus, said control means may comprise a regulator or switch operablyconnected to said heat source, whereby the power input to said heatsource may be controlled. In particular, where the heat source ispowered by electricity, said control means may be adapted forcontrolling the average voltage or amperage supplied to said source suchas to up- or down-regulate the temperature of said heat source. Thus,said control means may for example comprise a variable resistor, aswitch means, or a pulse width modulator such as an FET. Alternatively,or in addition, said control means may comprise a cooling means such asa heat sink which is operable when required to reduce the temperature ofthe heat source.

Alternatively, or in addition, said control means may be adapted toadjust the channelling of heat from said heat source to said end of thesmoking article, by selectively dispersing heat away from the end of thesmoking article and/or selectively directing heat towards the smokingarticle, as required. Thus, for example, said control means may comprisechannelling means such as a plurality of adjustable fins, whichchannelling means can be positioned in a first orientation whereby thechannelling means serve to disperse heat away from the end of thesmoking article and/or in a second orientation whereby the channellingmeans serve to direct heat towards the end of the smoking article, whichchannelling means may optionally be removable. Thus, for example, wherethe end of the smoking article is positioned at a greater distance fromthe heat source, said channelling means may be adjusted such as todirect heat towards the end of the smoking article, in order to enablesuccessful ignition of said smoking article by the heat source.Conversely, where the end of the smoking article is positioned at asmaller distance from the heat source, said channelling means may beadjusted such as to disperse heat away from the end of the smokingarticle, in order to enable successful ignition of said smoking articleby the heat source.

Said greater distance may denote a distance of more than about 2 mm, ormore than about 1.5 mm, or more than about 1 mm. Said smaller distancemay denote a distance of less than about 1 mm, or less than about 0.5mm.

Where said heat source is (alternatively or in addition) adapted foremitting heat for igniting said end of the smoking article byelectromagnetic radiation, said control means may be adapted forautomatically adjusting the level and/or the wavelength range ofelectromagnetic radiation that is applied by the heat source to the endof the smoking article for igniting the article, the adjustmentdepending upon the position of said end as detected by the sensor. Whenexposed to electromagnetic radiation, the end of a smoking article(which is typically primarily composed of tobacco) will absorb radiationin particular wavelength ranges according to its absorption spectrum.Radiation absorbed by the end of the smoking article will serve to heatthe end towards and beyond its ignition temperature, which may lead toignition. It is evident therefore that by selectively irradiating saidend of the smoking article with radiation in a wavelength range which isabsorbed by the end, and/or by increasing the overall level of radiationthat is applied to said end of the smoking article, the heating effectof the electromagnetic radiation on the end of the smoking article willbe enhanced. Conversely, by selectively irradiating said end of thesmoking article with radiation in a wavelength range which is notabsorbed or not efficiently absorbed by the end, and/or by decreasingthe overall level of radiation that is applied to said end of thesmoking article, the heating effect of the electromagnetic radiation onthe end of the smoking article will be diminished.

Said control means may therefore be adapted for automatically adjustingthe level and/or the wavelength range of electromagnetic radiation thatis emitted from the heat source. Adjustments in the level of radiationemitted may be readily achieved by adjusting the power input to saidheat source, so as to respectively increase or decrease the level ofradiation that is emitted by the heat source. Thus, said control meansmay comprise a switch or regulator operably connected to said heatsource for controlling the power input to said heat source. Adjustmentsin the wavelength range of electromagnetic radiation that is emitted bythe heat source may similarly be achieved through control of theoperation of the heat source. For example, where said heat sourcecomprises a halogen bulb, the halogen bulb will typically be configuredto enable the wavelength of the light emitted by the halogen bulb to beselected as required. Thus, said control means may be adapted forselecting an appropriate wavelength for generation by the halogen bulb.

Alternatively, or in addition, said control means may be adapted foradjusting the level and/or the wavelength range of electromagneticradiation that is transmitted from the heat source to the end of thesmoking article. In order to adjust the level of electromagneticradiation that is transmitted from the heat source to the end of thesmoking article, said control means may be adapted for adjustablyshielding and/or obscuring said heat source from said end of the smokingarticle, and/or for selectively focusing radiation emitted by said heatsource onto said end, and/or for selectively deflecting radiationemitted by said heat source away from said end. Thus, said control meansmay include adjustable shield means, such as an iris-type adjustableshield, which can be positioned and adjusted in order to shield aselected area of the heat source from the end of the smoking article.Said control means may include adjustable reflecting and/or refractingmeans which are adapted to selectively focus or direct radiation emittedfrom the heat source towards said end of the smoking article.Additionally or alternatively, said control means may compriseadjustable refracting and/or deflecting means which are adapted toselectively direct radiation emitted from the heat source away from theend of the smoking article. Additionally or alternatively, said controlmeans may comprise at least one thermal filter, which thermal filter isadapted to absorb or reflect a proportion of radiation impinging on thefilter, which thermal filter is arranged to be removably positionedbetween said heat source and the end of the smoking article such as toprevent the transmission of a proportion of radiation emitted from saidheat source towards said smoking article. Optionally, said control meansmay comprise a plurality of thermal filters, any number of which can bepositioned in parallel between said heat source and the end of thesmoking article. By altering the number of filters positioned betweensaid heat source and the smoking article, the quantity ofelectromagnetic radiation transmitted from the heat source to thesmoking article may be adjusted as required. Alternatively, said controlmeans may comprise one or more variable filters, each variable filterincluding a plurality of discrete areas with differentabsorption/reflection characteristics, such that by positioning thevariable filter between the heat source and the end of the smokingarticle and moving the variable filter relative to the heat source andthe smoking article, the quantity of electromagnetic radiationtransmitted from the heat source to the smoking article may be adjustedas required.

In addition or alternatively, in order to adjust the wavelength range ofthe electromagnetic radiation that is transmitted from the heat sourceto the end of the smoking article, said control means may comprise adichroic filter or a plurality of dichroic filters which are adapted forselectively reflecting or selectively transmitting electromagneticradiation in a specific wavelength range or ranges, which dichroicfilter or filters are arranged to be placed intermediate said heatsource and said end of the smoking article, for filtering radiationdirected from said heat source towards said end of the smoking article.A dichroic filter suitable for use in the present invention may, forexample, comprise a transparent substrate, such as a glass substrate,said substrate being provided with two or more layers of differentfilter media; the nature of the filter media and the thickness andarrangement of each of the layers being selected such that the filter iscapable of transmitting electromagnetic radiation only at certainwavelengths. Said layers of filter media may, for example, comprise oneor more layers of titanium dioxide, interspersed with one or more layersof silicon dioxide. In some embodiments, the nature of the filter mediaand the thickness and arrangement of the layers may vary across thesurface of the substrate, such that the reflection/transmissioncharacteristics of the dichroic filter vary across the surface of thefilter. Thus, said dichroic filter may be arranged to transmit through afirst portion of the filter only radiation in a first wavelength range,such as radiation in the range from 380 nm to 700 nm; and may bearranged to transmit through a second portion of the filter onlyradiation in a second wavelength range, such as radiation in the rangefrom 1200 nm to 2000 nm. Alternatively, a plurality of dichroic filtersmay be provided, each filter being arranged to transmit only radiationin a certain wavelength band, such as from 380 nm-800 nm, from 700 nm to1000 nm, from 900 nm to 1200 nm, and from 1100 nm to 1500 nm, and meansmay be provided for selectively placing a chosen one or more of saidfilters between the heat source and the end of the smoking article, suchthat only radiation of a particular predetermined wavelength range maybe transmitted from said heat source to said end of the smoking article.

Said control means may be adapted to automatically adjust the time forwhich heat is applied to the end of the smoking article for igniting thearticle, depending upon the location of said end.

Notwithstanding a larger separation between said heat source and saidend, successful ignition may for example be attained by lengthening theperiod during which heat is applied to the end of the article. Thus,said control means may be adapted for calculating the period of time forwhich heat should be applied to the end of the article for successfullyigniting said end, and for effectively terminating the application ofheat to said end after said period of time has elapsed. Said controlmeans may for example comprise switch means for respectively switchingon and/or off power input to said heat source in order to respectivelyinitiate or terminate the application of heat to said end.Alternatively, said control means may be adapted for respectivelyexposing or shielding, or for respectively installing or removing, saidheat source, or for otherwise respectively permitting or blocking theemission of heat by said heat source, in order to respectively initiateor terminate the application of heat to said end.

Said control means may be adapted to automatically adjust the timing ofthe application of heat with respect to the puff cycle of a smokingmachine, depending upon the position of said end of the smoking articleas detected by the sensor. Smoking machines operate by drawing airthrough a smoking article in regular bursts or “puffs”, typically onceevery 60 s or so. The period between the start of one puff and the startof the next puff is known as the “puff cycle”. The puff cycle consistsof a short puff, typically 2 s in duration, followed by a pause.

The optimal time for ignition of a smoking article is during the puffingphase of the puff cycle. Thus, by initiating the application of heat tothe end of a smoking article early in the puffing phase of the puffcycle, thereby lengthening the period of time during the puffing phasefor which heat is applied to the end, the likelihood of successfulignition, even where the heat source is positioned at a distance fromthe end of the article, may be increased. The likelihood of successfulignition may be yet further increased by initiating the application ofheat to the end of a smoking article just prior to the start of thepuffing phase. This will permit pre-heating of the end which will“prime” the end for ready ignition at the start of the puffing phase.

Hence, said control means may be arranged to be operatively connected toa smoking machine such as to detect and monitor the timing of the puffcycle, and may be arranged to control the relative timings of theinitiation of application of heat from the heat source to the end of thesmoking article and the start of the puff cycle, in order to ensuresuccessful ignition of said end. Said control means may therefore bearranged to control the timing of the initiation of application of heatfrom the heat source to the end of the smoking article, and/or thetiming of the start of the puff cycle, whereby the relative timings ofthese events may be controlled.

In some preferred embodiments, said sensor may be fixed in a knownposition with respect to said heat source, and may be adapted fordetecting said end of the smoking article when said end is in a desiredposition with respect to said heat source, and for transmitting adetection signal to said control means. Thus, said heat source and saidsensor may be movable with respect to said smoking article, and saidcontrol means may be adapted for terminating movement of said heatsource and said sensor with respect to said smoking article on receiptof said detection signal from said sensor. In this case, the sensor maybe conceptualised as “hunting” for the end of the smoking article.Alternatively or in addition, said smoking article may be movable withrespect to said heat source and said sensor, and said control means maybe adapted for terminating movement of said smoking article with respectto said heat source and said sensor on receipt of said detection signalfrom said sensor. In this case, the smoking article may beconceptualised as “probing” for the sensor.

Any sensor capable of detecting the end of said smoking article whensaid end is in a specified position is suitable for use in theseembodiments. For example, said sensor may comprise an emitter capable ofemitting a signal and a detector capable of receiving and detecting saidsignal from the emitter, the emitter and detector being arranged suchthat when said end is positioned between said emitter and said detector,transmission of said signal from said emitter to said detector isinterrupted, and said detection signal is triggered. The triggering ofthe detection signal accordingly signifies that the end of the smokingarticle is positioned between said emitter and said detector.Alternatively, said sensor may comprise an emitter capable of emitting asignal and a detector capable of receiving and detecting said signalfrom the emitter, the emitter and detector being arranged such that whensaid end is in a predetermined location relative to the emitter, saidsignal emitted from the emitter is reflected from said end and istransmitted to said detector for detection, and said detection signal istriggered. Accordingly, the triggering of the detection signal signifiesthat the end is in said predetermined position. Said signal may be anelectromagnetic wave signal, such as a laser signal, or a radiowave,microwave or visible light signal, or a sound wave signal such as anultrasonic wave signal. As yet a further alternative, said sensor may bea contact sensor which is adapted for detecting the end of a smokingarticle when said end contacts or moves out of contact with the sensor.

Alternatively, said sensor may be adapted for detecting signals causedby the proximity of said end; such as variations in air flow or airpressure, or variations in electrostatic or capacitive electric field;and for triggering said detection signal in response. The triggering ofthe detection signal will accordingly signify that said end is proximateto the sensor.

In other favourable embodiments, said sensor may be adapted foridentifying the position of said end of the smoking article amongst arange of possible locations. In one possible aspect, therefore, saidsensor may comprise a range-finding sensor, such as a laser or radarsensor, which is capable of transmitting signals which are adapted to bereflected from a target, detecting signals reflected from said target,and analysing said reflected signals, whereby the location of saidtarget can be calculated. Said range-finding sensor may be fixed in aknown position with respect to said heat source, and may be adapted foridentifying the location of said end with respect to said heat source.Alternatively, said range-finding sensor may be adapted to be fixed in aknown position with respect to said holding means, and may be adaptedfor measuring the location of said end of the smoking article withrespect to the holding means. In another possible aspect, said sensormay comprise any sensor as hereinabove defined which is capable ofdetecting the end of said smoking article when said end is in aspecified position, which sensor is adapted to be moved with respect tosaid heat source such as to hunt for said end, and means for identifyingthe position of the sensor with respect to said heat source, such thatthe location of said end, once detected by the sensor, can beidentified.

As yet a further alternative, said sensor may comprise a camera typedevice which is capable of visualising the smoking article and/or ashadow cast by the smoking article, whereby the position of the end ofthe smoking article may be detected.

In some embodiments, the arrangement may be such that said end of thesmoking article can be selectively shielded from said heat source, suchas to prevent substantial transfer of heat from said heat source to saidend. Thus, when the heat source and the smoking article are positionedfor ignition, said end may be shielded from the heat source and saidheat source may be energised without substantial transfer of heat fromthe heat source to the end during the course of energisation. Once theheat source is fully energised, said end may be exposed to the heatsource, thus enabling ignition of the end to take place.

Accordingly, said heat source may be adapted to move along a pre-setpath between a first exposed orientation, in which the heat source isarranged to face said end such that said end is exposed to the heatsource, and a second shielded orientation, in which the heat source isarranged to face away from said end such that said end is shielded fromsaid heat source. Alternatively, or in addition, one or more barriersformed from a heat-impermeable material may be provided for selectivelyshielding said end from said heat source. Said one or more barriers maybe adapted to be installed adjacent said heat source for shielding theheat source, and to be removed in order to expose said heat source.

Said control means may include control hardware which is programmed tocontrol the performance of the functions hereinabove defined. Inparticular, said control hardware may include processing means forreceiving said detection signal and for calculating the type and extentof adjustments which should be made to the components of the ignitionsystem and/or the smoking machine so as to enable successful ignition ofsaid smoking article, and for effecting said adjustments. Said controlhardware may be arranged to be located in a smoking machine, and/or insaid ignition system.

Said smoking article may be a rolled smoking article, such as acigarette, cigar or cigarillo. Suitably, said end of the smoking articlemay be the end which is ignited by a smoker in use; that is, thenon-filter end.

Preferably, said lighting system and said smoking machine may be capableof satisfying one or more ISO standards including ISO standard 3308(2000), and/or one or more FTC standards, and/or one or more CORESTAstandards, and/or any other applicable national or internationalstandards. Smoking machines suitable for use in conjunction with thepresent invention are widely available and in common use in the art.

Said smoking machine may be capable of holding a plurality of smokingarticles, and said lighting system may be adapted for igniting each ofsaid smoking articles consecutively. Preferably, said smoking machinemay be adapted for moving each smoking article which is to be ignited toa position such that the end of the smoking article is within a smalldistance, such as to within a few centimetres or a few millimetres, ofsaid ignition head, prior to detection of said end by the sensor andconsequent adjustment of the ignition head and/or the position of thesmoking article.

The components of said ignition system may be provided in the form of anintegral tool, or in the form of a kit of components which are adaptedto be assembled with one another and/or with a smoking machine, wherebythe ignition system can function as hereinabove described.

Following is a description, by way of example only and with reference tothe accompanying drawings, of embodiments of the present invention andmodes for putting the invention into effect.

In the drawings:

FIG. 1 shows a top view of an ignition system in accordance with theinvention, in the start position.

FIG. 2 shows a side view, partly cut away, of the ignition system ofFIG. 1.

FIG. 3 shows a top view of the ignition system of FIG. 1, afterdetection of a cigarette.

FIG. 4 shows a side view, partly cut away, of the ignition system ofFIG. 3.

FIG. 5 shows a top view of the ignition system of FIG. 1, at the pointof ignition.

FIG. 6 shows a side view, partly cut away, of the ignition system ofFIG. 5.

FIGS. 7 a to 7 c illustrate a mode of operation of the ignition systemshown in FIGS. 1-6.

FIG. 8(a) illustrates the start position for a mode of operation of asecond embodiment of an ignition system in accordance with theinvention.

FIG. 8(b) shows a top view of an ignition system as illustrated in FIG.8(a).

FIG. 8(c) shows a side view, partly cut away, of the ignition system ofFIG. 8(b).

FIG. 9(a) illustrates the probing position for a mode of operation ofthe ignition system shown in FIG. 8.

FIG. 9(b) shows a top view of an ignition system as illustrated in FIG.9(a).

FIG. 9(c) shows a side view, partly cut away, of the ignition system ofFIG. 9(b).

FIG. 10(a) illustrates the igniting position for a mode of operation ofthe ignition system shown in FIGS. 8 and 9.

FIG. 10(b) shows a top view of an ignition system as illustrated in FIG.10(a).

FIG. 10(c) shows a side view, partly cut away, of the ignition system ofFIG. 10(b).

FIGS. 1 a to 11 c illustrate an alternative mode of operation of anignition system in accordance with the present invention.

FIGS. 12 a and 12 b illustrate an alternative mode of operation of anignition system in accordance with the present invention.

FIG. 13 illustrates a variable dichroic filter for use in the presentinvention.

FIG. 14 illustrates an alternative mode of operation of an ignitionsystem in accordance with the present invention.

An embodiment of an ignition system in accordance with the presentinvention is shown in FIGS. 1-6. As seen in these Figures, the ignitionsystem comprises a base plate 1 which is adapted to be engaged with asmoking machine; an ignition head 2 for igniting cigarettes or othersmoking articles; and a break-beam sensor for detecting the end of asmoking article such as a cigarette, which sensor includes a beamemitter 3 and a beam detector 4.

Said ignition head 2 comprises a resistive coil 7, which resistive coil7 is adapted to be connected to a source of electrical power (notshown), whereby the coil 7 can be energised and heated to a temperaturesufficient for igniting a cigarette or other smoking article. As will beappreciated by the skilled man, the coil when heated will serve to emitheat both by air convection and by electromagnetic radiation. Resistivecoil 7 is mounted within a protective holder which is formed from aheat-insulating material such as a ceramic material. As seen in FIG. 2,said holder is substantially bowl-shaped, comprising an enclosing shieldwall 9 which defines an open mouth 10 by which the coil 7 is exposed.The base of said holder is gripped by a sleeve 13 formed from alightweight material such as aluminium.

Said ignition head 2 is mounted with respect to the base plate 1 suchthat said open mouth 10 points in a forwards direction away from thebase plate 1. As hereinafter described, the ignition head 2 is movableforwards and backwards with respect to the base plate 1, and ispivotable such that said open mouth 10 can be swung relative to the baseplate 1.

Said sleeve 13 comprises two pins 8 which protrude outwardly fromrespectively opposing sides of the sleeve 13. The pins are mounted tothe internal walls of a bracket 15, the arrangement being such that thesleeve 13 and the holder mounted therein can pivot relative to thebracket 15.

Said bracket 15 is rigidly connected on one side thereof to a pistonhead 5, which piston head 5 is mounted on a piston rod that is slidablewithin a first pneumatic cylinder 6, the arrangement being such thatsaid bracket 15 is slidable relative to said first pneumatic cylinder 6.Said first pneumatic cylinder 6 is bolted to said base plate 1 andextends forwardly away from said base plate 1, as illustrated in FIG. 1.The pneumatic cylinder is operable to cause the piston head 5, togetherwith said bracket 15 and said ignition head 2 which are mounted on thepiston head 5, to slide forwards and backwards with respect to the baseplate 1.

Said bracket 15 is rigidly connected on the other side thereof to asecond pneumatic cylinder 14. A piston rod 16 is slidably mounted withinsaid second pneumatic cylinder 14, and is slidable on operation of saidsecond pneumatic cylinder 14. The piston rod 16 is arranged to be activeon a block 12, whereby the block 12 can be propelled away from saidsecond pneumatic cylinder 14 on operation of said second pneumaticcylinder 14. As seen in FIG. 1, said second pneumatic cylinder 14 isoriented parallel to said first pneumatic cylinder 6, such that theoperation of said second pneumatic cylinder 14 results in forwardspropulsion of said block 12 relative to said bracket 15, and away fromthe base plate 1.

Said block 12 includes a slot 17 which accommodates a spindle 11. Saidspindle 11 extends laterally away from the block 12 and is rigidlyconnected to said sleeve 13. The arrangement is such that as said block12 is propelled forwardly away from the base plate 1, said spindle 11 iscaused to move transversely in a forwards direction away from the baseplate 1, and consequently said sleeve 13 and ignition head 2, beingpivotably mounted by way of said pins 8, is caused to pivot forwardlywith respect to said base plate 1, in a clockwise direction as shown inFIGS. 2 and 4.

A spring (not shown) is active on said ignition head 2, for biasing saidignition head 2 in an anticlockwise direction as shown in FIGS. 2 and 4.The configuration of said second pneumatic cylinder 14, said piston rod16 and said block 12 is such that when the piston rod 16 is fullywithdrawn into said second pneumatic cylinder 14, as shown in FIG. 2,the ignition head 2 is disposed at an angle of approximately 45° to saidbase plate 1. In this position, the open mouth 10 of the ignition head 2is shielded by way of a guard wall 18 as seen in FIG. 2, which guardwall 18 is fixedly mounted on said piston head 5. Said guard wall 18 isformed from a heat-reflective material such as stainless steel, and isshaped to correspond roughly to the shape of said open mouth 10, inorder to permit effective shielding of said mouth 10. Furtheranticlockwise rotation of said ignition head 2 beyond this shieldedposition is prohibited by the fixed position of said second pneumaticcylinder 14 on said bracket 15.

When said second pneumatic cylinder 14 is operated for propelling saidblock 12 and spindle 11 in a forwards direction, said ignition head 2 iscaused to pivot in a clockwise direction as shown in FIG. 2, against thebiasing force of said spring. The arrangement is such that when saidpiston rod 16 is fully extended from said second pneumatic cylinder 14,as shown in FIG. 4, the ignition head 2 is disposed such that said openmouth 10 faces forwardly away from the base plate 1. The ignition head 2is thus deployed for igniting a smoking article placed forwardly fromsaid base plate 1.

As seen in FIGS. 2 and 4, a second guard wall 19, formed from stainlesssteel, is fixed to said sleeve 13 of the ignition head 2, and serves toreduce peripheral heat loss from the open mouth 10, thereby diminishingundesired pre-heating of a smoking article prior to ignition.

As seen in the Figures, said beam emitter 3 and said beam detector 4 arefixedly mounted on respectively opposing sides of said bracket 15. Saidbeam emitter 3 is adapted for emitting a constant detectable signal,such as a beam of visible light, which beam is directed towards saidbeam detector 4. Beam detector 4 is capable of detecting and monitoringsaid beam. If and when an object, such as the end of a cigarette orother smoking article, extends between said beam emitter 3 and said beamdetector 4, the transmission of said beam from the beam emitter to thebeam detector is interrupted. Interruption of the beam is detected bythe beam detector. On interruption of the beam, the beam detector isconfigured to generate a detectable signal.

Said beam emitter 3 and detector 4 are conventional pieces of equipmentand are obtainable commercially from Sunx Ltd (distributors IndustrialControls (Anglia) Ltd).

The operation of each of said first pneumatic cylinder 6, said secondpneumatic cylinder 14, said sensor, and the power supply for energisingsaid resistive coil 7 is controlled by way of control hardware, whichmay include one or more microchips programmed to control the operationof these components as herein described. The control hardware isarranged to communicate with said sensor, the arrangement being suchthat said detectable signal generated by the sensor on detection of anobject is transmitted to the control hardware. Said control hardware isalso adapted for communicating with and controlling the operation of asmoking machine, as hereinbelow described. The control hardware may belocated in a smoking machine, or may be provided as part of the ignitionsystem. For example, the control hardware may comprise one or moresuitably programmed PICs or EPROMs.

The ignition system may be used for igniting cigarettes or other smokingarticles held by a smoking machine. Firstly, the smoking machine isprimed as follows. The base plate 1 of the ignition system is engagedwith a smoking machine that is primed with at least one smoking articlefor ignition. The base plate 1 may be engaged with an adjustablecomponent of the smoking machine, which component can be adjusted suchas to move the system towards said smoking article to within a few cm ora few mm of the end of said article. The smoking machine mayadditionally or as an alternative be arranged for moving said smokingarticle towards said system, to within a few cm or a few mm of saidignition system.

A mode of operation of the ignition system for detecting and ignitingthe smoking article is illustrated in FIGS. 7 a to 7 c, and is describedin more detail below. Owing to the biasing action of said spring (notshown), the ignition system initially rests in the start position asillustrated in FIGS. 1 and 2, with the ignition head 2 in the shieldedposition. To prime the ignition system for use, said control hardwareinstructs the switching-on of the power source for said resistive coil7, such that said coil is energised and heated for ignition. Saidcontrol hardware also instructs the switching-on of said sensor.

If the sensor detects the end of the smoking article between saidemitter 3 and said detector 4, a detectable signal is generated by saiddetector 4 as hereinabove described. This detectable signal istransmitted by said sensor to said control hardware, prompting thecontrol hardware to instruct the smoking machine to move the ignitionsystem in a backwards direction, away from said end of the smokingarticle. When the sensor no longer detects the end of the smokingarticle between said emitter 3 and said detector 4, the sensor transmitsa second detectable signal to the control hardware (or ceasestransmission of the first detectable signal to the control hardware),prompting the control hardware to instruct the smoking machine to stopmoving the ignition system in a backwards direction.

If the sensor does not detect the end of the smoking article betweensaid emitter 3 and said detector 4, no signal is transmitted by saidsensor to the control hardware, and the control hardware accordinglyinstructs the smoking machine to move the ignition system in a forwardsdirection, towards the end of the smoking article. Upon detection of theend of the smoking article between said emitter 3 and said detector 4during forwards propulsion of said ignition system, a signal istransmitted from said sensor to the control hardware, and said hardwareinstructs said smoking machine to halt further forwards propulsion ofsaid ignition system towards the smoking article.

Owing to the construction and arrangement of a smoking machine, the onlyobject which may normally be detected by said sensor during normaloperation of the equipment is the end of a smoking article such as acigarette which is held by the smoking machine. Accordingly, in normaloperation, the detection of any object between said emitter 3 and saiddetector 4 signals the detection of the end of said smoking article.

Once the end of the smoking article has been detected, and forwardspropulsion of the ignition system has ceased as described above, thecontrol hardware instructs the switching-on of said first pneumaticcylinder 6 and said second pneumatic cylinder 14. Each of said firstpneumatic cylinder 6 and said second pneumatic cylinder 14 is fittedwith a flow restrictor which controls the rate of response of therespective pneumatic cylinder. The flow restrictor fitted to said secondpneumatic cylinder 14 is adapted to bring about a rapid response, whilstthe flow restrictor fitted to said first pneumatic cylinder 6 is adaptedto bring about a slower response. Thus, when said hardware instructs theswitching-on of said second pneumatic cylinder 14, this cylinderresponds quickly, propelling said block 12 and spindle 11 forwards suchas to propel said ignition head 2 in a clockwise direction against thebias of the spring, from said shielded position into the deployedposition. Conversely, when said hardware instructs the switching-on ofsaid first pneumatic cylinder 6, this cylinder responds more slowly,propelling said piston head 5 bearing said bracket 15 and ignition head2 forwardly away from said base plate 1. As illustrated in FIG. 6, thepiston head 5 continues to move forwardly until the piston 14 contacts astop 35 provided on a plate rigidly attached to said base plate 1.Further forwards movement of said piston head 5 is thereafter blocked bythe stop 35.

The components of the ignition system are configured such that when thepiston 14 contacts the stop 35 as described above, the ignition head 2is located such that a predetermined separation exists between theresistive coil 7 and the end of the smoking article, so as to permiteffective ignition of the smoking article by the heated coil. Typically,the ignition head will be located such that the coil 7 is 0.5-1.0 mmfrom the end of said smoking article. However, said predeterminedseparation between the coil and the end of the smoking article may befreely selected as required by the operator, by appropriate adjustmentof the position of said stop 35 prior to initiation of the ignitionoperation. In order to adjust the position of said adjustable stopcorrectly, prior to initiation of the ignition operation, the operatormay place a smoking article between said emitter and detector such thatthe end of said article can be detected by the sensor, and may thenposition the ignition head 2 such that the unheated coil is at aselected distance from the end of said smoking article, the stop 35 thenbeing adjusted such that forwards movement of the ignition head 2 beyondthis position is prevented.

A second embodiment of an ignition system in accordance with the presentinvention is shown in FIGS. 8-10. In these Figures, components common tothe embodiments shown in FIGS. 1-6 are referenced with the samereference numerals. Further detailed description of these components andtheir operation is not necessary.

In contrast to the embodiment shown in FIGS. 1-6, the embodiment shownin FIGS. 8-10 is arranged for operating in “real time”. Thus, whilst theignition system shown in FIGS. 1-6 is arranged such that the position ofthe smoking article is detected and appropriate adjustments to theignition system are made whilst the ignition head is in the shieldedposition and the coil is energised, the ignition head being thereafteradapted to be moved along a predetermined path into position forigniting a smoking article, the ignition system shown in FIGS. 8-10 isin contrast arranged such that the position of the smoking article isdetected and appropriate adjustments to the ignition system are madewhilst the ignition head is in the deployed position and the coil isenergised. Accordingly, in the latter embodiments, a smoking article thesmoking article will be ignited as the ignition head reaches thepredetermined location relative to the smoking article.

Accordingly, following priming of the smoking machine as hereinabovedescribed, the control hardware of the embodiment shown in FIGS. 8-10 isarranged first to instruct the switching-on of said second pneumaticcylinder 14, whereby the ignition head 2 is caused to move from saidshielded position (FIG. 8) into said deployed position (FIG. 9) ashereinabove described. Thereafter, the control hardware instructs theswitching-on of said first pneumatic cylinder 6, such that said pistonhead 5 and the components mounted thereon are caused to move forwardlyaway from said base plate 1.

As seen in FIGS. 8 b and 8 c, a braking mechanism is provided forbraking the movement of said piston head 5 relative to said pneumaticcylinder 6. A pneumatic braking cylinder 20 is mounted to said baseplate 1, whilst a brake strip 22 is mounted to said piston head 5 andextends parallel to said cylinder 6. Said pneumatic braking cylinder 20is operatively connected to a braking shoe 21, such that on actuation ofsaid braking cylinder 20, the braking shoe 21 presses said braking strip22 against said first pneumatic cylinder 6, hence braking the movementof said piston head 5 relative to said first pneumatic cylinder 6.

The operation of said pneumatic braking cylinder 20 is controlled bysaid control hardware. The arrangement is such that when said sensordetects the end of a smoking article and a detectable signal istransmitted to said control hardware, the control hardware instructs theswitching-off of said first pneumatic cylinder 6 and the switching-on ofsaid pneumatic braking cylinder 20. Conveniently, these switchingoperations may be performed simultaneously by means of a valve mechanismwhich is adapted to switch the pneumatic supply from said firstpneumatic cylinder 6 to said pneumatic braking cylinder 14 in responseto a command from said control hardware.

The double effect of switching off the first pneumatic cylinder 6 andswitching on the braking cylinder 20 causes said ignition head 2 to comerapidly to a halt following detection of an end of a smoking article bythe sensor. The ignition system is configured such that the resistivecoil 7 of the ignition system is a predetermined distance, such as0.5-11.0 mm, from the end of the smoking article, in order to permiteffective ignition of the smoking article by the heated resistive coil.

An alternative mode of operation of a ignition system in accordance withthe invention is illustrated in FIGS. 11 a to 11 c. As will be evidentfrom the following description, this mode of operation is useful only inconjunction with a smoking machine in which the position of the smokingarticles held by the machine may be altered. According to this mode,linear movement of the ignition head and sensor may not be required.Hence, whilst either of the ignition systems respectively shown in FIGS.1-6 and in FIGS. 8-10 may be operated according to this mode,alternative embodiments in which the cylinder 6 is, for example,replaced with a non-adjustable mounting arm, may also be operatedaccording to the mode hereinbelow described.

According to this mode, the ignition system is engaged with a smokingmachine having adjustable cigarette holders. The control hardware of theignition system is arranged to communicate with the smoking machine suchthat the control hardware is capable of controlling the movement of atleast one adjustable cigarette holder of the smoking machine. Theignition head 2 is placed in the start position as shown in FIG. 11 a,and the resistive coil is energised under the control of the controlhardware.

A cigarette or other smoking article 30 is inserted into said cigaretteholder, and under the control of the control hardware, the cigaretteholder is moved towards the ignition head. When the end of the smokingarticle is detected by the sensor, as illustrated in FIG. 11 b, a signalis transmitted to the control hardware as hereinabove described, andsaid control hardware instructs the cigarette holder to cease moving.The ignition head 2 is then moved into the deployed position under thecontrol of the control hardware, as hereinabove described, and isoptionally also moved a short predetermined distance towards or awayfrom the base plate 1, also under the control of the control hardware.The arrangement is such that when the end of the smoking article isdetectable by the sensor, and once the ignition head has been moved fromthe shielded position into the deployed position and has optionally beenmoved a short predetermined distance towards or away from the baseplate, then the coil of the ignition head will be at a predetermineddistance from the end of the smoking article, in order to enablesuccessful ignition of the smoking article by the coil. Typically, thepredetermined distance between the coil and the end of the smokingarticle will be 0.5-1.0 mm.

It will be appreciated that the embodiments and modes of operationhereinabove described work by detecting the end of a smoking articlewhen it has reached a predetermined location with respect to theignition head, and thereafter (if necessary) moving the ignition head ina predetermined manner such as to dispose the ignition head in therequired position and orientation for ignition. Various otherembodiments and modes of operation may also be envisaged by the skilledman which work on the same principle, and all such embodiments and modesare encompassed within the scope of this invention.

An alternative embodiment and mode of operation of the invention isillustrated in FIGS. 12 a and 12 b. The embodiment shown in theseFigures is similar in many respects to the embodiment shown in FIGS.1-6, and in these respects will not be further described. Featuresparticular to the embodiment shown in FIGS. 12 a and 12 b arehereinbelow described.

As seen in FIGS. 12 a and 12 b, an ignition system in accordance withthe invention comprises an ignition head 2 which is adjustably mounted,in the manner hereinbefore described, on a base plate 1. Adjustment ofthe position and orientation of said ignition head relative to the baseplate 1 is controlled by control hardware (not shown).

The ignition system comprises a sensor 25 which is adapted to take oneor more measurements for determining the distance between the end of asmoking article 30 within a holder 31 for use in a smoking machine, anda known point on the holder. Thus, the sensor 25 may be adapted to bepositioned on or adjacent a smoking machine. Said sensor 25 is adaptedto communicate with said control hardware and to transmit to saidcontrol hardware information regarding said measurement. Said sensormay, for example, comprise a range-finding sensor such as a lasersensor.

The control hardware of the ignition system is adapted for processingsaid information, and for making adjustments to the position andorientation of the ignition head 2, such that when the holder andsmoking article have been installed in the smoking machine, and theignition system and/or holder have been moved by the smoking machineinto proximity with one another, the ignition head is positioned at apredetermined distance from the end of the smoking article protrudingfrom the holder.

It will be appreciated by the skilled man that the embodiments and modesof the invention hereinabove described rely solely on adjustments to therelative positions of the resistive coil and the end of a smokingarticle at the point of ignition, for improving the success of ignition.Nevertheless, in knowledge of the position of the end of a smokingarticle, having been detected by a sensor as hereinabove described,adjustments can also or instead be made by the control hardware to theoperation of the resistive coil, whereby the success of ignition may beimproved.

For example, if the position of the end of a smoking article held by asmoking machine and in position for ignition is determined to be morethan a specified distance (such as about 11.0 mm, or about 1.5 mm, orabout 2 mm) from the position of the resistive coil at the point ofignition, then the power generated by the coil, and/or the powertransmitted to the end of the smoking article, and/or the length of timefor which the end of the smoking article is exposed to the coil, mayeach be appropriately increased, in order to compensate for the greaterseparation between the coil and the end of the smoking article, and toensure successful ignition of the smoking article notwithstanding thisincreased separation. As a further alternative, the end of the smokingarticle may be exposed to the heated coil earlier in the puff cycle ofthe smoking machine, such as at or towards the start of the puff orshortly before the start of the puff. As a further alternative, thewavelength range of electromagnetic radiation transmitted to said endmay be selected to be a wavelength that is efficiently absorbed by saidend.

Conversely, if the position of the end of a smoking article held by asmoking machine and in position for ignition is determined to be lessthan a specified distance (such as about 1 mm) from the position of theresistive coil at the point of ignition, then the power generated by thecoil, and/or the power transmitted to the end of the smoking article,and/or the length of time for which the end of the smoking article isexposed to the coil, may each be appropriately reduced, in order tocompensate for the smaller separation between the coil and the end ofthe smoking article, and to reduce the likelihood of heat damage to thesmoking article during the course of ignition, notwithstanding thisreduced separation. As a further alternative, the end of the smokingarticle may be exposed to the heated coil later in the puff cycle of thesmoking machine, such as towards the middle or the end of the puff. As afurther alternative, a dichroic filter may be provided for filtering outelectromagnetic radiation having a wavelength which is absorbed by theend of the smoking article, in order that the end of the smoking articleis not exposed to such radiation.

A variable dichroic filter 41 suitable for this purpose is shown in FIG.13. As seen in this Figure, the dichroic filter 41 comprises a glasssubstrate 33, which substrate is coated with a layer of silicon dioxide34, a layer of titanium dioxide 35, a second layer of silicon dioxide36, a second layer of titanium dioxide 37, a layer of a neutral densityfilter medium 38, and a clear film layer 39. The layers are covered witha protective glass covering 40.

As seen in FIG. 13, the thickness of each layer of silicon dioxide andtitanium dioxide varies across the surface of the substrate 33, and thethickness of the layer of neutral density filter medium 38 also variesacross the surface of the substrate 33. The juxtaposition of the layersand the variation in their thicknesses means that different areas of thefilter will transmit electromagnetic radiation within different specificwavelength bands, all other wavelengths being reflected. The variabledichroic filter 41 may therefore be positioned between the coil and theend of the smoking article, as seen in FIG. 14, and may be movedrelative to the coil and the smoking article under the control of thecontrol hardware, in order to vary the wavelength of radiationtransmitted from the coil to the smoking article as desired. Accordingto the absorption spectrum of the end of the smoking article, certainwavelengths of radiation will be efficiently absorbed by the end of thesmoking article, whilst other wavelengths will be largely or entirelyreflected. Accordingly, the heating power of the radiation which istransmitted to the end of the smoking article may be varied using thedichroic filter as desired.

The control hardware of the ignition system may be adapted so as to becapable of calculating any adjustments required to the operation of theresistive coil in view of the position of the end of the smokingarticle, and for controlling the outworking of such adjustments. Forexample, the power generated by the coil may be up- or down-regulated bycontrolling the power input, such as the voltage applied, to theresistive coil, such as by way of a variable resistor.

The timing and duration of the application of heat to the end of thesmoking article may conveniently be controlled under the control of thecontrol hardware by way of a movable shield, or by way of switch meansconnected to the power input to the coil, although the latter may beless effective owing to the cooling time required for the coil.

The positioning of any filters or shields relative to said coil and theend of said smoking article is also controlled by the control hardware.

The provision of control hardware and the programming of said hardwaresuch that the hardware is capable of instructing and controlling theoperation of the ignition system as described above is a routine taskwithin the capability of the man skilled in the art.

1-25. (canceled)
 26. An ignition system for a smoking machine, comprising: a heat source that is adapted to emit heat in order to ignite one end of a smoking article which is held by a smoking machine; an automatic sensor which is adapted to detect the position of said end of the smoking article; and a control unit in communication with said sensor, which is adapted to adjust automatically a parameter of the operation of said heat source depending on the position of said end as detected by said sensor, such as to enable successful ignition of said end by said heat source.
 27. An ignition system as claimed in claim 26, wherein said heat source is adapted to emit heat by air convection in order to ignite said end of the smoking article, and said control unit is adapted to adjust automatically the temperature of the heat source, the adjustment depending upon the location of said end, as detected by the sensor.
 28. An ignition system as claimed in claim 26, wherein said control unit is adapted to adjust channelling of heat from said heat source to said end of the smoking article.
 29. An ignition system as claimed in claim 28, wherein said channeling comprises one of dispersing heat away from the end of the smoking article and directing heat towards the smoking article, as required.
 30. An ignition system as claimed in claim 26, wherein said heat source is adapted to emit heat in order to ignite said end of the smoking article by electromagnetic radiation, and said control unit is adapted to adjust automatically the level of electromagnetic radiation that is applied by the heat source to the end of the smoking article for igniting the article, the adjustment depending upon the position of said end as detected by the sensor.
 31. An ignition system as claimed in claim 30, wherein said control unit is adapted to adjust automatically the level of electromagnetic radiation that is emitted from the heat source.
 32. An ignition system as claimed in claim 30, wherein said control unit is adapted to adjust the level of electromagnetic radiation that is transmitted from the heat source to the end of the smoking article.
 33. An ignition system as claimed in claim 30, wherein said system includes an adjustable shield which can be positioned and adjusted in order to shield a selected area of the heat source from the end of the smoking article.
 34. An ignition system as claimed in claim 30, wherein said system includes an adjustable reflector or refractor which is adapted to selectively focus or direct radiation emitted from the heat source towards said end of the smoking article.
 35. An ignition system as claimed in claim 26, wherein said heat source is adapted to emit heat in order to ignite said end of the smoking article by electromagnetic radiation, and said control unit is adapted to adjust automatically the wavelength range of electromagnetic radiation that is applied by the heat source to the end of the smoking article for igniting the article, the adjustment depending upon the position of said end as detected by the sensor.
 36. An ignition system as claimed in claim 35, wherein said control unit is adapted to adjust automatically the wavelength range of electromagnetic radiation that is emitted from the heat source.
 37. An ignition system as claimed in claim 35, wherein said system comprises at least one thermal filter, which thermal filter is adapted to absorb or reflect a proportion of radiation impinging on the filter, which thermal filter is arranged to be removably positioned between said heat source and the end of the smoking article such as to prevent the transmission of a proportion of radiation emitted from said heat source towards said smoking article.
 38. An ignition system as claimed in claim 35, wherein said system comprises at least one filter, each filter including a plurality of discrete areas with different absorption/reflection characteristics, such that by positioning the filter between the heat source and the end of the smoking article and moving the filter relative to the heat source and the smoking article, the quantity of electromagnetic radiation transmitted from the heat source to the smoking article may be adjusted as required.
 39. An ignition system as claimed in claim 26, wherein said control unit is adapted to automatically adjust the time for which heat is applied to the end of the smoking article for igniting the article, depending upon the location of said end.
 40. An ignition system as claimed in claim 26, wherein said control unit is adapted to automatically adjust the timing of the application of heat with respect to the puff cycle of a smoking machine, depending upon the position of said end of the smoking article as detected by the sensor.
 41. An ignition system as claimed in claim 26, wherein said control unit is further adapted to automatically adjust relative movement of said heat source and said smoking article, such that a predetermined distance separates said heat source from said end of the smoking article, whereby said end of the smoking article can be successfully ignited by the heat source.
 42. An ignition system as claimed in claim 26, said end of the smoking article can be selectively shielded from said heat source, such as to prevent substantial transfer of heat from said heat source to said end.
 43. An ignition system according to claim 26, wherein the sensor is arranged to detect radiation reflected from or emitted by the smoking article.
 44. An ignition system for a smoking machine, comprising: a heat source that is adapted to emit heat for igniting one end of a smoking article which is held by a smoking machine; an automatic sensor which is adapted to detect the position of said end of the smoking article; and a control unit in communication with said sensor, which is adapted to adjust automatically at least one of a parameter of the operation of said heat source, and relative movement of said heat source and of said article, depending on the position of said end as detected by said sensor, such as to enable successful ignition of said end by said heat source; wherein the sensor is arranged to detect radiation reflected from or emitted by the smoking article.
 45. An ignition system according to claim 44, wherein said sensor comprises a range finding sensor which is adapted to transmit signals which are able to be reflected from a target, to detect signals reflected from said target, and to analyse said reflected signals.
 46. An ignition system according to claim 44, wherein said sensor comprises a camera type device which is capable of visualising the smoking article.
 47. A smoking machine comprising a holder which holds a smoking article such as to expose one end thereof, a puffing unit which draws air through the smoking article, and an ignition system, the ignition system comprising: a heat source that is adapted to emit heat in order to ignite one end of a smoking article which is held by a smoking machine; an automatic sensor which is adapted to detect the position of said end of the smoking article; and a control unit in communication with said sensor, which is adapted to adjust automatically a parameter of the operation of said heat source depending on the position of said end as detected by said sensor, such as to enable successful ignition of said end by said heat source.
 48. A smoking machine as claimed in claim 47, which machine is arranged to hold a plurality of smoking articles, and said lighting system is adapted to ignite each of said smoking articles consecutively.
 49. A smoking machine as claimed in claim 47, which machine is adapted to move each smoking article which is to be ignited to a position such that the end of the smoking article is within a small distance of said ignition head prior to detection of said end by the sensor and consequent adjustment of a parameter of the operation of said heat source. 